[cmake-developers] [CMake] CMake 2.8.12.201401116 is much slower than 2.8.12.1

[Clinton Stimpson]

On Thursday, January 16, 2014 10:14:32 AM Bill Hoffman wrote:
> Moving this to cmake-developers list:
> 
> On 1/16/2014 9:55 AM, Clinton Stimpson wrote:
> > On one of my projects, I see ~3.0 seconds for CMake 2.8.12 and ~3.8
> > seconds
> > for CMake master.  I don't have an idea why, but with my test, it doesn't
> > see like "much" slower.
> 
> 3.8 from 3.0 is much slower in my book....  :)
> 
> change it to minutes... 3 minutes vs 3.8 minutes is a big jump...
> 
> Looking at the test timing on the bootstrap test on a slow machine, this
> seems to be a point that got slower:
> 
> http://open.cdash.org/testDetails.php?test=229000913&build=3172685   885
> seconds
> http://open.cdash.org/testDetails.php?test=229192425&build=3173776   902
> seconds
> 
> -Bill

For this one project I got 3.0 seconds -> 3.8 seconds.
I narrowed it down to this commit:

commit 2509c7678feb2efab79a384fd0b0b35cee8d02b0
Author: Stephen Kelly <steveire at gmail.com>
Date:   Mon Jan 13 13:04:03 2014 +0100
    Qt4: Use generator expression in COMPILE_DEFINITIONS (#14692)




I'm surprised how this small change added a 20% slowdown.
-set_property(DIRECTORY APPEND PROPERTY COMPILE_DEFINITIONS_DEBUG QT_DEBUG)
+set_property(DIRECTORY APPEND PROPERTY COMPILE_DEFINITIONS $<$<NOT:
$<CONFIG:Debug>>:QT_NO_DEBUG>)

-- 
Clinton Stimpson
Elemental Technologies, Inc
Computational Simulation Software, LLC
www.csimsoft.com